[apple/xnu.git] / osfmk / i386 / cpu_threads.c

/*
 * Copyright (c) 2003-2016 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
#include <vm/vm_kern.h>
#include <kern/kalloc.h>
#include <kern/timer_queue.h>
#include <mach/machine.h>
#include <i386/cpu_threads.h>
#include <i386/cpuid.h>
#include <i386/machine_cpu.h>
#include <i386/pmCPU.h>
#include <i386/bit_routines.h>

#if MONOTONIC
#include <kern/monotonic.h>
#endif /* MONOTONIC */

#define DIVISOR_GUARD(denom)                            \
        if ((denom) == 0) {                             \
                kprintf("%s: %d Zero divisor: " #denom, \
                        __FILE__, __LINE__);            \
        }

static void debug_topology_print(void);

boolean_t       topo_dbg = FALSE;

x86_pkg_t       *x86_pkgs               = NULL;
uint32_t        num_Lx_caches[MAX_CACHE_DEPTH]  = { 0 };

static x86_pkg_t        *free_pkgs      = NULL;
static x86_die_t        *free_dies      = NULL;
static x86_core_t       *free_cores     = NULL;
static uint32_t         num_dies        = 0;

static x86_cpu_cache_t  *x86_caches     = NULL;
static uint32_t         num_caches      = 0;

static boolean_t        topoParmsInited = FALSE;
x86_topology_parameters_t       topoParms;

decl_simple_lock_data(, x86_topo_lock);
 
static struct cpu_cache {
        int     level;  int     type;
} cpu_caches [LCACHE_MAX] = {
        [L1D] = {       1,      CPU_CACHE_TYPE_DATA },
        [L1I] = {       1,      CPU_CACHE_TYPE_INST },
        [L2U] = { 2,    CPU_CACHE_TYPE_UNIF },
        [L3U] = { 3,    CPU_CACHE_TYPE_UNIF },
};

static boolean_t
cpu_is_hyperthreaded(void)
{
    i386_cpu_info_t     *cpuinfo;

    cpuinfo = cpuid_info();
    return(cpuinfo->thread_count > cpuinfo->core_count);
}

static x86_cpu_cache_t *
x86_cache_alloc(void)
{
    x86_cpu_cache_t     *cache;
    int                 i;

    if (x86_caches == NULL) {
        cache = kalloc(sizeof(x86_cpu_cache_t) + (MAX_CPUS * sizeof(x86_lcpu_t *)));
        if (cache == NULL)
            return(NULL);
    } else {
        cache = x86_caches;
        x86_caches = cache->next;
        cache->next = NULL;
    }

    bzero(cache, sizeof(x86_cpu_cache_t));
    cache->next = NULL;
    cache->maxcpus = MAX_CPUS;
    for (i = 0; i < cache->maxcpus; i += 1) {
        cache->cpus[i] = NULL;
    }

    num_caches += 1;

    return(cache);
}
 
static void
x86_LLC_info(void)
{
    int                 cache_level     = 0;
    uint32_t            nCPUsSharing    = 1;
    i386_cpu_info_t     *cpuinfo;
    struct cpu_cache    *cachep;
    int                 i;

    cpuinfo = cpuid_info();

    for (i = 0, cachep = &cpu_caches[0]; i < LCACHE_MAX; i++, cachep++) {

        if (cachep->type == 0 || cpuid_info()->cache_size[i] == 0)
            continue;

        /*
         * Only worry about it if it's a deeper level than
         * what we've seen before.
         */
        if (cachep->level > cache_level) {
            cache_level = cachep->level;

            /*
             * Save the number of CPUs sharing this cache.
             */
            nCPUsSharing = cpuinfo->cache_sharing[i];
        }
    }

    /*
     * Make the level of the LLC be 0 based.
     */
    topoParms.LLCDepth = cache_level - 1;

    /*
     * nCPUsSharing represents the *maximum* number of cores or
     * logical CPUs sharing the cache.
     */
    topoParms.maxSharingLLC = nCPUsSharing;

    topoParms.nCoresSharingLLC = nCPUsSharing / (cpuinfo->thread_count /
                                                 cpuinfo->core_count);
    topoParms.nLCPUsSharingLLC = nCPUsSharing;

    /*
     * nCPUsSharing may not be the number of *active* cores or
     * threads that are sharing the cache.
     */
    if (nCPUsSharing > cpuinfo->core_count)
        topoParms.nCoresSharingLLC = cpuinfo->core_count;
    if (nCPUsSharing > cpuinfo->thread_count)
        topoParms.nLCPUsSharingLLC = cpuinfo->thread_count;
}

static void
initTopoParms(void)
{
    i386_cpu_info_t     *cpuinfo;

    topoParms.stable = FALSE;

    cpuinfo = cpuid_info();

    PE_parse_boot_argn("-topo", &topo_dbg, sizeof(topo_dbg));

    /*
     * We need to start with getting the LLC information correct.
     */
    x86_LLC_info();

    /*
     * Compute the number of threads (logical CPUs) per core.
     */
    DIVISOR_GUARD(cpuinfo->core_count);
    topoParms.nLThreadsPerCore = cpuinfo->thread_count / cpuinfo->core_count;
    DIVISOR_GUARD(cpuinfo->cpuid_cores_per_package);
    topoParms.nPThreadsPerCore = cpuinfo->cpuid_logical_per_package / cpuinfo->cpuid_cores_per_package;

    /*
     * Compute the number of dies per package.
     */
     DIVISOR_GUARD(topoParms.nCoresSharingLLC);
    topoParms.nLDiesPerPackage = cpuinfo->core_count / topoParms.nCoresSharingLLC;
    DIVISOR_GUARD(topoParms.nPThreadsPerCore);
    DIVISOR_GUARD(topoParms.maxSharingLLC / topoParms.nPThreadsPerCore);
    topoParms.nPDiesPerPackage = cpuinfo->cpuid_cores_per_package / (topoParms.maxSharingLLC / topoParms.nPThreadsPerCore);


    /*
     * Compute the number of cores per die.
     */
    topoParms.nLCoresPerDie = topoParms.nCoresSharingLLC;
    topoParms.nPCoresPerDie = (topoParms.maxSharingLLC / topoParms.nPThreadsPerCore);

    /*
     * Compute the number of threads per die.
     */
    topoParms.nLThreadsPerDie = topoParms.nLThreadsPerCore * topoParms.nLCoresPerDie;
    topoParms.nPThreadsPerDie = topoParms.nPThreadsPerCore * topoParms.nPCoresPerDie;

    /*
     * Compute the number of cores per package.
     */
    topoParms.nLCoresPerPackage = topoParms.nLCoresPerDie * topoParms.nLDiesPerPackage;
    topoParms.nPCoresPerPackage = topoParms.nPCoresPerDie * topoParms.nPDiesPerPackage;

    /*
     * Compute the number of threads per package.
     */
    topoParms.nLThreadsPerPackage = topoParms.nLThreadsPerCore * topoParms.nLCoresPerPackage;
    topoParms.nPThreadsPerPackage = topoParms.nPThreadsPerCore * topoParms.nPCoresPerPackage;

    TOPO_DBG("\nCache Topology Parameters:\n");
    TOPO_DBG("\tLLC Depth:           %d\n", topoParms.LLCDepth);
    TOPO_DBG("\tCores Sharing LLC:   %d\n", topoParms.nCoresSharingLLC);
    TOPO_DBG("\tThreads Sharing LLC: %d\n", topoParms.nLCPUsSharingLLC);
    TOPO_DBG("\tmax Sharing of LLC:  %d\n", topoParms.maxSharingLLC);

    TOPO_DBG("\nLogical Topology Parameters:\n");
    TOPO_DBG("\tThreads per Core:  %d\n", topoParms.nLThreadsPerCore);
    TOPO_DBG("\tCores per Die:     %d\n", topoParms.nLCoresPerDie);
    TOPO_DBG("\tThreads per Die:   %d\n", topoParms.nLThreadsPerDie);
    TOPO_DBG("\tDies per Package:  %d\n", topoParms.nLDiesPerPackage);
    TOPO_DBG("\tCores per Package: %d\n", topoParms.nLCoresPerPackage);
    TOPO_DBG("\tThreads per Package: %d\n", topoParms.nLThreadsPerPackage);

    TOPO_DBG("\nPhysical Topology Parameters:\n");
    TOPO_DBG("\tThreads per Core: %d\n", topoParms.nPThreadsPerCore);
    TOPO_DBG("\tCores per Die:     %d\n", topoParms.nPCoresPerDie);
    TOPO_DBG("\tThreads per Die:   %d\n", topoParms.nPThreadsPerDie);
    TOPO_DBG("\tDies per Package:  %d\n", topoParms.nPDiesPerPackage);
    TOPO_DBG("\tCores per Package: %d\n", topoParms.nPCoresPerPackage);
    TOPO_DBG("\tThreads per Package: %d\n", topoParms.nPThreadsPerPackage);

    topoParmsInited = TRUE;
}

static void
x86_cache_free(x86_cpu_cache_t *cache)
{
    num_caches -= 1;
    if (cache->level > 0 && cache->level <= MAX_CACHE_DEPTH)
        num_Lx_caches[cache->level - 1] -= 1;
    cache->next = x86_caches;
    x86_caches = cache;
}

/*
 * This returns a list of cache structures that represent the
 * caches for a CPU.  Some of the structures may have to be
 * "freed" if they are actually shared between CPUs.
 */
static x86_cpu_cache_t *
x86_cache_list(void)
{
    x86_cpu_cache_t     *root   = NULL;
    x86_cpu_cache_t     *cur    = NULL;
    x86_cpu_cache_t     *last   = NULL;
    struct cpu_cache    *cachep;
    int                 i;

    /*
     * Cons up a list driven not by CPUID leaf 4 (deterministic cache params)
     * but by the table above plus parameters already cracked from cpuid...
     */
    for (i = 0, cachep = &cpu_caches[0]; i < LCACHE_MAX; i++, cachep++) {

        if (cachep->type == 0 || cpuid_info()->cache_size[i] == 0)
            continue;
        
        cur = x86_cache_alloc();
        if (cur == NULL)
            break;

        cur->type       = cachep->type;
        cur->level      = cachep->level;
        cur->nlcpus     = 0;
        cur->maxcpus    = cpuid_info()->cache_sharing[i];
        cur->partitions = cpuid_info()->cache_partitions[i];
        cur->cache_size = cpuid_info()->cache_size[i];
        cur->line_size  = cpuid_info()->cache_linesize;

        if (last == NULL) {
            root = cur;
            last = cur;
        } else {
            last->next = cur;
            last = cur;
        }
        num_Lx_caches[cur->level - 1] += 1;
    }
    return root;
}


static x86_cpu_cache_t *
x86_match_cache(x86_cpu_cache_t *list, x86_cpu_cache_t *matcher)
{
    x86_cpu_cache_t     *cur_cache;
 
    cur_cache = list;
    while (cur_cache != NULL) {
        if (cur_cache->maxcpus  == matcher->maxcpus
            && cur_cache->type  == matcher->type
            && cur_cache->level == matcher->level
            && cur_cache->partitions == matcher->partitions
            && cur_cache->line_size  == matcher->line_size
            && cur_cache->cache_size == matcher->cache_size)
            break;

        cur_cache = cur_cache->next;
    }

    return(cur_cache);
}

static void
x86_lcpu_init(int cpu)
{
    cpu_data_t          *cpup;
    x86_lcpu_t          *lcpu;
    int                 i;

    cpup = cpu_datap(cpu);

    lcpu = &cpup->lcpu;
    lcpu->lcpu = lcpu;
    lcpu->cpu  = cpup;
    lcpu->next_in_core = NULL;
    lcpu->next_in_die  = NULL;
    lcpu->next_in_pkg  = NULL;
    lcpu->core         = NULL;
    lcpu->die          = NULL;
    lcpu->package      = NULL;
    lcpu->cpu_num = cpu;
    lcpu->lnum = cpu;
    lcpu->pnum = cpup->cpu_phys_number;
    lcpu->state = LCPU_OFF;
    for (i = 0; i < MAX_CACHE_DEPTH; i += 1)
        lcpu->caches[i] = NULL;
}

static x86_core_t *
x86_core_alloc(int cpu)
{
    x86_core_t  *core;
    cpu_data_t  *cpup;

    cpup = cpu_datap(cpu);

    mp_safe_spin_lock(&x86_topo_lock);
    if (free_cores != NULL) {
        core = free_cores;
        free_cores = core->next_in_die;
        core->next_in_die = NULL;
        simple_unlock(&x86_topo_lock);
    } else {
        simple_unlock(&x86_topo_lock);
        core = kalloc(sizeof(x86_core_t));
        if (core == NULL)
            panic("x86_core_alloc() kalloc of x86_core_t failed!\n");
    }

    bzero((void *) core, sizeof(x86_core_t));

    core->pcore_num = cpup->cpu_phys_number / topoParms.nPThreadsPerCore;
    core->lcore_num = core->pcore_num % topoParms.nPCoresPerPackage;

    core->flags = X86CORE_FL_PRESENT | X86CORE_FL_READY
                | X86CORE_FL_HALTED | X86CORE_FL_IDLE;

    return(core);
}

static void
x86_core_free(x86_core_t *core)
{
    mp_safe_spin_lock(&x86_topo_lock);
    core->next_in_die = free_cores;
    free_cores = core;
    simple_unlock(&x86_topo_lock);
}

static x86_pkg_t *
x86_package_find(int cpu)
{
    x86_pkg_t   *pkg;
    cpu_data_t  *cpup;
    uint32_t    pkg_num;

    cpup = cpu_datap(cpu);

    pkg_num = cpup->cpu_phys_number / topoParms.nPThreadsPerPackage;

    pkg = x86_pkgs;
    while (pkg != NULL) {
        if (pkg->ppkg_num == pkg_num)
            break;
        pkg = pkg->next;
    }

    return(pkg);
}
 
static x86_die_t *
x86_die_find(int cpu)
{
    x86_die_t   *die;
    x86_pkg_t   *pkg;
    cpu_data_t  *cpup;
    uint32_t    die_num;

    cpup = cpu_datap(cpu);

    die_num = cpup->cpu_phys_number / topoParms.nPThreadsPerDie;

    pkg = x86_package_find(cpu);
    if (pkg == NULL)
        return(NULL);

    die = pkg->dies;
    while (die != NULL) {
        if (die->pdie_num == die_num)
            break;
        die = die->next_in_pkg;
    }

    return(die);
}

static x86_core_t *
x86_core_find(int cpu)
{
    x86_core_t  *core;
    x86_die_t   *die;
    cpu_data_t  *cpup;
    uint32_t    core_num;

    cpup = cpu_datap(cpu);

    core_num = cpup->cpu_phys_number / topoParms.nPThreadsPerCore;

    die = x86_die_find(cpu);
    if (die == NULL)
        return(NULL);

    core = die->cores;
    while (core != NULL) {
        if (core->pcore_num == core_num)
            break;
        core = core->next_in_die;
    }

    return(core);
}
 
void
x86_set_logical_topology(x86_lcpu_t *lcpu, int pnum, int lnum)
{
    x86_core_t  *core = lcpu->core;
    x86_die_t   *die  = lcpu->die;
    x86_pkg_t   *pkg  = lcpu->package;
    
    assert(core != NULL);
    assert(die != NULL);
    assert(pkg != NULL);

    lcpu->cpu_num = lnum;
    lcpu->pnum = pnum;
    lcpu->master = (lnum == master_cpu);
    lcpu->primary = (lnum % topoParms.nLThreadsPerPackage) == 0;

    lcpu->lnum = lnum % topoParms.nLThreadsPerCore;

    core->pcore_num = lnum / topoParms.nLThreadsPerCore;
    core->lcore_num = core->pcore_num % topoParms.nLCoresPerDie;

    die->pdie_num = lnum / (topoParms.nLThreadsPerCore*topoParms.nLCoresPerDie);
    die->ldie_num = die->pdie_num % topoParms.nLDiesPerPackage;

    pkg->ppkg_num = lnum / topoParms.nLThreadsPerPackage;
    pkg->lpkg_num = pkg->ppkg_num;

}

static x86_die_t *
x86_die_alloc(int cpu)
{
    x86_die_t   *die;
    cpu_data_t  *cpup;

    cpup = cpu_datap(cpu);

    mp_safe_spin_lock(&x86_topo_lock);
    if (free_dies != NULL) {
        die = free_dies;
        free_dies = die->next_in_pkg;
        die->next_in_pkg = NULL;
        simple_unlock(&x86_topo_lock);
    } else {
        simple_unlock(&x86_topo_lock);
        die = kalloc(sizeof(x86_die_t));
        if (die == NULL)
            panic("x86_die_alloc() kalloc of x86_die_t failed!\n");
    }

    bzero((void *) die, sizeof(x86_die_t));

    die->pdie_num = cpup->cpu_phys_number / topoParms.nPThreadsPerDie;

    die->ldie_num = num_dies;
    atomic_incl((long *) &num_dies, 1);

    die->flags = X86DIE_FL_PRESENT;
    return(die);
}

static void
x86_die_free(x86_die_t *die)
{
    mp_safe_spin_lock(&x86_topo_lock);
    die->next_in_pkg = free_dies;
    free_dies = die;
    atomic_decl((long *) &num_dies, 1);
    simple_unlock(&x86_topo_lock);
}

static x86_pkg_t *
x86_package_alloc(int cpu)
{
    x86_pkg_t   *pkg;
    cpu_data_t  *cpup;

    cpup = cpu_datap(cpu);

    mp_safe_spin_lock(&x86_topo_lock);
    if (free_pkgs != NULL) {
        pkg = free_pkgs;
        free_pkgs = pkg->next;
        pkg->next = NULL;
        simple_unlock(&x86_topo_lock);
    } else {
        simple_unlock(&x86_topo_lock);
        pkg = kalloc(sizeof(x86_pkg_t));
        if (pkg == NULL)
            panic("x86_package_alloc() kalloc of x86_pkg_t failed!\n");
    }

    bzero((void *) pkg, sizeof(x86_pkg_t));

    pkg->ppkg_num = cpup->cpu_phys_number / topoParms.nPThreadsPerPackage;

    pkg->lpkg_num = topoParms.nPackages;
    atomic_incl((long *) &topoParms.nPackages, 1);

    pkg->flags = X86PKG_FL_PRESENT | X86PKG_FL_READY;
    return(pkg);
}

static void
x86_package_free(x86_pkg_t *pkg)
{
    mp_safe_spin_lock(&x86_topo_lock);
    pkg->next = free_pkgs;
    free_pkgs = pkg;
    atomic_decl((long *) &topoParms.nPackages, 1);
    simple_unlock(&x86_topo_lock);
}

static void
x86_cache_add_lcpu(x86_cpu_cache_t *cache, x86_lcpu_t *lcpu)
{
    x86_cpu_cache_t     *cur_cache;
    int                 i;

    /*
     * Put the new CPU into the list of the cache.
     */
    cur_cache = lcpu->caches[cache->level - 1];
    lcpu->caches[cache->level - 1] = cache;
    cache->next = cur_cache;
    cache->nlcpus += 1;
    for (i = 0; i < cache->nlcpus; i += 1) {
        if (cache->cpus[i] == NULL) {
            cache->cpus[i] = lcpu;
            break;
        }
    }
}

static void
x86_lcpu_add_caches(x86_lcpu_t *lcpu)
{
    x86_cpu_cache_t     *list;
    x86_cpu_cache_t     *cur;
    x86_cpu_cache_t     *match;
    x86_die_t           *die;
    x86_core_t          *core;
    x86_lcpu_t          *cur_lcpu;
    uint32_t            level;
    boolean_t           found           = FALSE;

    assert(lcpu != NULL);

    /*
     * Add the cache data to the topology.
     */
    list = x86_cache_list();

    mp_safe_spin_lock(&x86_topo_lock);

    while (list != NULL) {
        /*
         * Remove the cache from the front of the list.
         */
        cur = list;
        list = cur->next;
        cur->next = NULL;
        level = cur->level - 1;

        /*
         * If the cache isn't shared then just put it where it
         * belongs.
         */
        if (cur->maxcpus == 1) {
            x86_cache_add_lcpu(cur, lcpu);
            continue;
        }

        /*
         * We'll assume that all of the caches at a particular level
         * have the same sharing.  So if we have a cache already at
         * this level, we'll just skip looking for the match.
         */
        if (lcpu->caches[level] != NULL) {
            x86_cache_free(cur);
            continue;
        }

        /*
         * This is a shared cache, so we have to figure out if
         * this is the first time we've seen this cache.  We do
         * this by searching through the topology and seeing if
         * this cache is already described.
         *
         * Assume that L{LLC-1} are all at the core level and that
         * LLC is shared at the die level.
         */
        if (level < topoParms.LLCDepth) {
            /*
             * Shared at the core.
             */
            core = lcpu->core;
            cur_lcpu = core->lcpus;
            while (cur_lcpu != NULL) {
                /*
                 * Skip ourselves.
                 */
                if (cur_lcpu == lcpu) {
                    cur_lcpu = cur_lcpu->next_in_core;
                    continue;
                }

                /*
                 * If there's a cache on this logical CPU,
                 * then use that one.
                 */
                match = x86_match_cache(cur_lcpu->caches[level], cur);
                if (match != NULL) {
                    x86_cache_free(cur);
                    x86_cache_add_lcpu(match, lcpu);
                    found = TRUE;
                    break;
                }

                cur_lcpu = cur_lcpu->next_in_core;
            }
        } else {
            /*
             * Shared at the die.
             */
            die = lcpu->die;
            cur_lcpu = die->lcpus;
            while (cur_lcpu != NULL) {
                /*
                 * Skip ourselves.
                 */
                if (cur_lcpu == lcpu) {
                    cur_lcpu = cur_lcpu->next_in_die;
                    continue;
                }

                /*
                 * If there's a cache on this logical CPU,
                 * then use that one.
                 */
                match = x86_match_cache(cur_lcpu->caches[level], cur);
                if (match != NULL) {
                    x86_cache_free(cur);
                    x86_cache_add_lcpu(match, lcpu);
                    found = TRUE;
                    break;
                }

                cur_lcpu = cur_lcpu->next_in_die;
            }
        }

        /*
         * If a shared cache wasn't found, then this logical CPU must
         * be the first one encountered.
         */
        if (!found) {
            x86_cache_add_lcpu(cur, lcpu);
        }
    }

    simple_unlock(&x86_topo_lock);
}

static void
x86_core_add_lcpu(x86_core_t *core, x86_lcpu_t *lcpu)
{
    assert(core != NULL);
    assert(lcpu != NULL);

    mp_safe_spin_lock(&x86_topo_lock);

    lcpu->next_in_core = core->lcpus;
    lcpu->core = core;
    core->lcpus = lcpu;
    core->num_lcpus += 1;
    simple_unlock(&x86_topo_lock);
}

static void
x86_die_add_lcpu(x86_die_t *die, x86_lcpu_t *lcpu)
{
    assert(die != NULL);
    assert(lcpu != NULL);
 
    lcpu->next_in_die = die->lcpus;
    lcpu->die = die;
    die->lcpus = lcpu;
}

static void
x86_die_add_core(x86_die_t *die, x86_core_t *core)
{
    assert(die != NULL);
    assert(core != NULL);

    core->next_in_die = die->cores;
    core->die = die;
    die->cores = core;
    die->num_cores += 1;
}

 static void
x86_package_add_lcpu(x86_pkg_t *pkg, x86_lcpu_t *lcpu)
{
    assert(pkg != NULL);
    assert(lcpu != NULL);

    lcpu->next_in_pkg = pkg->lcpus;
    lcpu->package = pkg;
    pkg->lcpus = lcpu;
}

static void
x86_package_add_core(x86_pkg_t *pkg, x86_core_t *core)
{
    assert(pkg != NULL);
    assert(core != NULL);

    core->next_in_pkg = pkg->cores;
    core->package = pkg;
    pkg->cores = core;
}

static void
x86_package_add_die(x86_pkg_t *pkg, x86_die_t *die)
{
    assert(pkg != NULL);
    assert(die != NULL);

    die->next_in_pkg = pkg->dies;
    die->package = pkg;
    pkg->dies = die;
    pkg->num_dies += 1;
}

void *
cpu_thread_alloc(int cpu)
{
    x86_core_t  *core           = NULL;
    x86_die_t   *die            = NULL;
    x86_pkg_t   *pkg            = NULL;
    cpu_data_t  *cpup;
    uint32_t    phys_cpu;

    /*
     * Only allow one to manipulate the topology at a time.
     */
    mp_safe_spin_lock(&x86_topo_lock);

    /*
     * Make sure all of the topology parameters have been initialized.
     */
    if (!topoParmsInited)
        initTopoParms();

    cpup = cpu_datap(cpu);

    phys_cpu = cpup->cpu_phys_number;

    x86_lcpu_init(cpu);

    /*
     * Assume that all cpus have the same features.
     */
    if (cpu_is_hyperthreaded()) {
        cpup->cpu_threadtype = CPU_THREADTYPE_INTEL_HTT;
    } else {
        cpup->cpu_threadtype = CPU_THREADTYPE_NONE;
    }

    /*
     * Get the package that the logical CPU is in.
     */
    do {
        pkg = x86_package_find(cpu);
        if (pkg == NULL) {
            /*
             * Package structure hasn't been created yet, do it now.
             */
            simple_unlock(&x86_topo_lock);
            pkg = x86_package_alloc(cpu);
            mp_safe_spin_lock(&x86_topo_lock);
            if (x86_package_find(cpu) != NULL) {
                x86_package_free(pkg);
                continue;
            }
            
            /*
             * Add the new package to the global list of packages.
             */
            pkg->next = x86_pkgs;
            x86_pkgs = pkg;
        }
    } while (pkg == NULL);

    /*
     * Get the die that the logical CPU is in.
     */
    do {
        die = x86_die_find(cpu);
        if (die == NULL) {
            /*
             * Die structure hasn't been created yet, do it now.
             */
            simple_unlock(&x86_topo_lock);
            die = x86_die_alloc(cpu);
            mp_safe_spin_lock(&x86_topo_lock);
            if (x86_die_find(cpu) != NULL) {
                x86_die_free(die);
                continue;
            }

            /*
             * Add the die to the package.
             */
            x86_package_add_die(pkg, die);
        }
    } while (die == NULL);

    /*
     * Get the core for this logical CPU.
     */
    do {
        core = x86_core_find(cpu);
        if (core == NULL) {
            /*
             * Allocate the core structure now.
             */
            simple_unlock(&x86_topo_lock);
            core = x86_core_alloc(cpu);
            mp_safe_spin_lock(&x86_topo_lock);
            if (x86_core_find(cpu) != NULL) {
                x86_core_free(core);
                continue;
            }

            /*
             * Add the core to the die & package.
             */
            x86_die_add_core(die, core);
            x86_package_add_core(pkg, core);
            machine_info.physical_cpu_max += 1;
        }
    } while (core == NULL);

    
    /*
     * Done manipulating the topology, so others can get in.
     */
    machine_info.logical_cpu_max += 1;
    simple_unlock(&x86_topo_lock);

    /*
     * Add the logical CPU to the other topology structures.
     */
    x86_core_add_lcpu(core, &cpup->lcpu);
    x86_die_add_lcpu(core->die, &cpup->lcpu);
    x86_package_add_lcpu(core->package, &cpup->lcpu);
    x86_lcpu_add_caches(&cpup->lcpu);

    return (void *) core;
}

void
cpu_thread_init(void)
{
    int         my_cpu          = get_cpu_number();
    cpu_data_t  *cpup           = current_cpu_datap();
    x86_core_t  *core;
    static int  initialized     = 0;

    /*
     * If we're the boot processor, we do all of the initialization of
     * the CPU topology infrastructure.
     */
    if (my_cpu == master_cpu && !initialized) {
        simple_lock_init(&x86_topo_lock, 0);

        /*
         * Put this logical CPU into the physical CPU topology.
         */
        cpup->lcpu.core = cpu_thread_alloc(my_cpu);

        initialized = 1;
    }

    /*
     * Do the CPU accounting.
     */
    core = cpup->lcpu.core;
    mp_safe_spin_lock(&x86_topo_lock);
    machine_info.logical_cpu += 1;
    if (core->active_lcpus == 0)
        machine_info.physical_cpu += 1;
    core->active_lcpus += 1;
    simple_unlock(&x86_topo_lock);

    pmCPUMarkRunning(cpup);
    timer_resync_deadlines();
}

/*
 * Called for a cpu to halt permanently
 * (as opposed to halting and expecting an interrupt to awaken it).
 */
__attribute__((noreturn))
void
cpu_thread_halt(void)
{
    x86_core_t  *core;
    cpu_data_t  *cpup = current_cpu_datap();

    mp_safe_spin_lock(&x86_topo_lock);
    machine_info.logical_cpu -= 1;
    core = cpup->lcpu.core;
    core->active_lcpus -= 1;
    if (core->active_lcpus == 0)
        machine_info.physical_cpu -= 1;
    simple_unlock(&x86_topo_lock);

    /*
     * Let the power management code determine the best way to "stop"
     * the processor.
     */
    ml_set_interrupts_enabled(FALSE);
    while (1) {
        pmCPUHalt(PM_HALT_NORMAL);
    }
    /* NOT REACHED */
}

/*
 * Validates that the topology was built correctly.  Must be called only
 * after the complete topology is built and no other changes are being made.
 */
void
x86_validate_topology(void)
{
    x86_pkg_t           *pkg;
    x86_die_t           *die;
    x86_core_t          *core;
    x86_lcpu_t          *lcpu;
    uint32_t            nDies;
    uint32_t            nCores;
    uint32_t            nCPUs;

    if (topo_dbg)
        debug_topology_print();

    /*
     * XXX
     *
     * Right now this only works if the number of CPUs started is the total
     * number of CPUs.  However, when specifying cpus=n the topology is only
     * partially constructed and the checks below will fail.
     *
     * We should *always* build the complete topology and only start the CPUs
     * indicated by cpus=n.  Until that happens, this code will not check the
     * topology if the number of cpus defined is < that described the the
     * topology parameters.
     */
    nCPUs = topoParms.nPackages * topoParms.nLThreadsPerPackage;
    if (nCPUs > real_ncpus)
        return;

    pkg = x86_pkgs;
    while (pkg != NULL) {
        /*
         * Make sure that the package has the correct number of dies.
         */
        nDies = 0;
        die = pkg->dies;
        while (die != NULL) {
            if (die->package == NULL)
                panic("Die(%d)->package is NULL",
                      die->pdie_num);
            if (die->package != pkg)
                panic("Die %d points to package %d, should be %d",
                      die->pdie_num, die->package->lpkg_num, pkg->lpkg_num);

            TOPO_DBG("Die(%d)->package %d\n",
                die->pdie_num, pkg->lpkg_num);

            /*
             * Make sure that the die has the correct number of cores.
             */
            TOPO_DBG("Die(%d)->cores: ", die->pdie_num);
            nCores = 0;
            core = die->cores;
            while (core != NULL) {
                if (core->die == NULL)
                    panic("Core(%d)->die is NULL",
                          core->pcore_num);
                if (core->die != die)
                    panic("Core %d points to die %d, should be %d",
                          core->pcore_num, core->die->pdie_num, die->pdie_num);
                nCores += 1;
                TOPO_DBG("%d ", core->pcore_num);
                core = core->next_in_die;
            }
            TOPO_DBG("\n");

            if (nCores != topoParms.nLCoresPerDie)
                panic("Should have %d Cores, but only found %d for Die %d",
                      topoParms.nLCoresPerDie, nCores, die->pdie_num);

            /*
             * Make sure that the die has the correct number of CPUs.
             */
            TOPO_DBG("Die(%d)->lcpus: ", die->pdie_num);
            nCPUs = 0;
            lcpu = die->lcpus;
            while (lcpu != NULL) {
                if (lcpu->die == NULL)
                    panic("CPU(%d)->die is NULL",
                          lcpu->cpu_num);
                if (lcpu->die != die)
                    panic("CPU %d points to die %d, should be %d",
                          lcpu->cpu_num, lcpu->die->pdie_num, die->pdie_num);
                nCPUs += 1;
                TOPO_DBG("%d ", lcpu->cpu_num);
                lcpu = lcpu->next_in_die;
            }
            TOPO_DBG("\n");

            if (nCPUs != topoParms.nLThreadsPerDie)
                panic("Should have %d Threads, but only found %d for Die %d",
                      topoParms.nLThreadsPerDie, nCPUs, die->pdie_num);

            nDies += 1;
            die = die->next_in_pkg;
        }

        if (nDies != topoParms.nLDiesPerPackage)
            panic("Should have %d Dies, but only found %d for package %d",
                  topoParms.nLDiesPerPackage, nDies, pkg->lpkg_num);

        /*
         * Make sure that the package has the correct number of cores.
         */
        nCores = 0;
        core = pkg->cores;
        while (core != NULL) {
            if (core->package == NULL)
                panic("Core(%d)->package is NULL",
                      core->pcore_num);
            if (core->package != pkg)
                panic("Core %d points to package %d, should be %d",
                      core->pcore_num, core->package->lpkg_num, pkg->lpkg_num);
            TOPO_DBG("Core(%d)->package %d\n",
                core->pcore_num, pkg->lpkg_num);

            /*
             * Make sure that the core has the correct number of CPUs.
             */
            nCPUs = 0;
            lcpu = core->lcpus;
            TOPO_DBG("Core(%d)->lcpus: ", core->pcore_num);
            while (lcpu != NULL) {
                if (lcpu->core == NULL)
                    panic("CPU(%d)->core is NULL",
                          lcpu->cpu_num);
                if (lcpu->core != core)
                    panic("CPU %d points to core %d, should be %d",
                          lcpu->cpu_num, lcpu->core->pcore_num, core->pcore_num);
                TOPO_DBG("%d ", lcpu->cpu_num);
                nCPUs += 1;
                lcpu = lcpu->next_in_core;
            }
            TOPO_DBG("\n");

            if (nCPUs != topoParms.nLThreadsPerCore)
                panic("Should have %d Threads, but only found %d for Core %d",
                      topoParms.nLThreadsPerCore, nCPUs, core->pcore_num);
            nCores += 1;
            core = core->next_in_pkg;
        }

        if (nCores != topoParms.nLCoresPerPackage)
            panic("Should have %d Cores, but only found %d for package %d",
                  topoParms.nLCoresPerPackage, nCores, pkg->lpkg_num);

        /*
         * Make sure that the package has the correct number of CPUs.
         */
        nCPUs = 0;
        lcpu = pkg->lcpus;
        while (lcpu != NULL) {
            if (lcpu->package == NULL)
                panic("CPU(%d)->package is NULL",
                      lcpu->cpu_num);
            if (lcpu->package != pkg)
                panic("CPU %d points to package %d, should be %d",
                      lcpu->cpu_num, lcpu->package->lpkg_num, pkg->lpkg_num);
            TOPO_DBG("CPU(%d)->package %d\n",
                lcpu->cpu_num, pkg->lpkg_num);
            nCPUs += 1;
            lcpu = lcpu->next_in_pkg;
        }

        if (nCPUs != topoParms.nLThreadsPerPackage)
            panic("Should have %d Threads, but only found %d for package %d",
                  topoParms.nLThreadsPerPackage, nCPUs, pkg->lpkg_num);

        pkg = pkg->next;
    }
}

/*
 * Prints out the topology
 */
static void
debug_topology_print(void)
{
    x86_pkg_t           *pkg;
    x86_die_t           *die;
    x86_core_t          *core;
    x86_lcpu_t          *cpu;

    pkg = x86_pkgs;
    while (pkg != NULL) {
        kprintf("Package:\n");
        kprintf("    Physical: %d\n", pkg->ppkg_num);
        kprintf("    Logical:  %d\n", pkg->lpkg_num);

        die = pkg->dies;
        while (die != NULL) {
            kprintf("    Die:\n");
            kprintf("        Physical: %d\n", die->pdie_num);
            kprintf("        Logical:  %d\n", die->ldie_num);

            core = die->cores;
            while (core != NULL) {
                kprintf("        Core:\n");
                kprintf("            Physical: %d\n", core->pcore_num);
                kprintf("            Logical:  %d\n", core->lcore_num);

                cpu = core->lcpus;
                while (cpu != NULL) {
                    kprintf("            LCPU:\n");
                    kprintf("                CPU #:    %d\n", cpu->cpu_num);
                    kprintf("                Physical: %d\n", cpu->pnum);
                    kprintf("                Logical:  %d\n", cpu->lnum);
                    kprintf("                Flags:    ");
                    if (cpu->master)
                        kprintf("MASTER ");
                    if (cpu->primary)
                        kprintf("PRIMARY");
                    if (!cpu->master && !cpu->primary)
                        kprintf("(NONE)");
                    kprintf("\n");

                    cpu = cpu->next_in_core;
                }

                core = core->next_in_die;
            }

            die = die->next_in_pkg;
        }

        pkg = pkg->next;
    }
}